Relocatable radiation vault and methods of assembly and use

ABSTRACT

A temporary radiotherapy facility for use during renovation, upgrading, and/or modernization of an existing facility. The radiotherapy facility is integrated with radiation producing equipment and radiation shielding vaults. The structural elements and their arrangement enable compliance with applicable codes for this type of facility and provide an ability to maintain radiotherapy treatment continuity during equipment transition.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of PCT/US2010/054601 filed Oct. 29,2010, which claims the benefit of U.S. Provisional Application No.61/256,984, filed Oct. 31, 2009, the disclosures of which areincorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a complete radiation therapy facility,including a therapeutic radiation producing (or emitting) device and theshielding structures necessary to safely produce the therapeuticradiation and methods for making and using the same. More particularly,but not exclusively, the present invention relates to a radiotherapyvault and integrated clinical functions suitable for use on a temporarybasis, such as during the time an existing facility is undergoing anequipment upgrade or facility renovation. The various structuralfeatures which are illustrated and described herein result,collectively, in a fully equipped and integrated radiotherapy clinicalfacility. A further structural feature of the disclosed integratedsolution is the overall size compactness given the performance demandsand requirements.

Radiation emitting equipment has a number of well known applications.Radiation emitting equipment is used to inspect packages and cargo atborders and to perform non-destructive testing. In the medical field,radiation emitting equipment is used in the diagnosis and treatment of anumber of diseases. Not surprisingly, the manufacturers of thisequipment are continually making improvements. Radiation emitted byequipment of the type described as “therapeutic” or “for treatment” isoften referred to as “high energy”, and is typically greater than 1 mv.

For example, radiation therapy (a.k.a. radiotherapy) has become widelyused in the treatment of cancer and several other non-malignantconditions, and modern radiotherapy equipment has improved abilities totarget and destroy specific tissues while sparing surrounding healthytissue. As a result, the use of up-to-date radiotherapy equipment canyield improved patient outcomes as well as provide other benefits to theoperators of the facility, such as increased ease of use, increasedefficiency, and/or increased patient throughput.

Despite these benefits, it has not been practical for many existingradiotherapy facilities to modernize. Existing radiotherapy equipment,like many other types of radiation emitting equipment, is typicallyhoused within a radiation shielding vault so as to protect thesurrounding personnel from the harmful effects of the radiation. Becauseof the high radiation levels involved (i.e. typically greater than 1 MV)existing vaults are often constructed underground and/or with concretewalls that are several feet thick. As a result, the process of removingexisting equipment, installing a modern replacement unit, and performingany necessary remodeling and reconfiguration is typically a three tofive month process, with some projects taking up to a year. The prospectof a radiotherapy facility being out of service for such an extendedduration, with the resultant disruption of treatment to patients, lossof revenue to the facility, and potential loss of referrals, is simplyunacceptable to many facility operators. As a result, it is estimatedthat there are thousands of medical linear accelerators in use todaywhich are technically obsolete and in need of immediate replacement.

In one form, the present invention addresses this need.

BRIEF SUMMARY

The present invention provides systems and techniques for constructingand using integrated radiotherapy treatment facilities which includeradiation producing equipment and radiation shielding vaults. While theactual nature of the invention covered herein can only be determinedwith reference to the claims appended hereto, certain aspects of theinvention that are characteristic of the embodiments disclosed hereinare described briefly as follows.

According to one aspect, the present invention provides a temporary,building code compliant radiotherapy facility for use during the timewhen an existing facility is being upgraded or modernized.

According to another aspect, the present invention provides a method ofmaintaining radiotherapy treatment continuity during an equipmenttransition.

According to another aspect, the present invention provides a buildingcode compliant temporary radiotherapy facility which can be erected andput into use rapidly and cost effectively.

According to another aspect, the present invention provides a new methodof constructing a foundation for radiation shielding vaults.

According to another aspect, the present invention provides a new methodof coupling a radiation shielding vault to a foundation.

According to another aspect, the present invention provides a newapproach for supporting radiation shielding material over a treatmentarea and distributing the load of that radiation shielding material to asupporting foundation.

According to another aspect, the present invention provides for theconstruction of a radiotherapy facility wherein the foundation whichsupports the treatment room is decoupled from the foundation whichsupports the mass of radiation shielding material above the treatmentroom.

According to another aspect, the present invention provides a new designfor providing a roof over a radiation treatment vault.

According to another aspect, the present invention provides a newmechanism for installing the shielding door for a vault.

According to another aspect, the present invention integrates requiredclinical, radiotherapy room and accelerator equipment with requiredelectrical and mechanical support systems in a singular compact andcomplete solution.

These and other aspects are discussed below.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Although the characteristic features of this invention will beparticularly pointed out in the claims, the invention itself, and themanner in which it may be made and used, may be better understood byreferring to the following description taken in connection with theaccompanying figures forming a part thereof.

FIG. 1 shows the floor plan of a completed radiotherapy facilityaccording to one embodiment.

FIG. 2 is a side elevational view, in full section, of the FIG. 1facility.

FIG. 3 is an end elevational view, in full section, of the FIG. 1facility.

FIG. 4 is a top plan view layout of the foundation for the FIG. 1facility.

FIG. 5 is a partial, end sectional view of the foundation as viewedalong line 5-5 in FIG. 4.

FIG. 6 is a diagrammatic perspective view showing the installation of asupport in a foundation beam.

FIG. 7 is a diagrammatic perspective view showing the installation ofanother support in a foundation beam.

FIG. 8 is a diagrammatic perspective view showing the installation ofsupports in a concrete slab as per existing installations of the systemcorresponding to U.S. Pat. No. 6,973,758 (the Rad Pro).

FIG. 9 is an elevational view showing the radiation shielding doorcassette installed in the facility of FIG. 1.

FIG. 10 is a partial, top view, as viewed along line 10-10 in FIG. 9.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is hereby intended. Alterations and further modifications inthe illustrated devices, and such further applications of the principlesof the invention as illustrated herein are contemplated as wouldnormally occur to one skilled in the art to which the invention relates.

General Overview

In one form, the present invention involves the provision of a fullyfunctioning temporary radiotherapy facility intended for short term use.The temporary facility may be provided at a designated site and used totreat patients during the time when an existing radiotherapy facility isbeing upgraded or modernized. Upon completion of the upgrade, thetemporary facility may be removed from the site and redeployed toanother site in need of a similar service.

Referring to FIGS. 1-3, temporary radiotherapy facility 10 includes atreatment room 20 including a radiotherapy device 25 and a controlstation 22 for the radiotherapy device 25. The interior of facility 10includes waiting area 30, reception/scheduling area 31, gowning area 35,restroom 34, and storage areas 32, 38. The mechanical area 33 containsany necessary heating and chiller equipment and is accessed externally,as is an additional storage area 36. The facility further includes anelectrical closet 27, staff sink 28 and a potable and waste water tanks29.

Access to treatment room 20 is via a radiation shielded door 40 andcorridor 37. Once inside the treatment room 20, the patient lies on thetreatment table 24 and the radiotherapy is administered via radiotherapydevice 25 in accordance with the treatment parameters input by theoperator at the control station 22.

When fully constructed, the facility 10 complies with applicablebuilding codes. Further, the facility 10 is “habitable” in the contextof supporting patients and medical personnel during the time of use. Asused herein, “code compliant” and “building codes” are intended toencompass an ability to construct and configure the basic structuralelements of the disclosed combination so as to meet or adhere to whatwould be required according to applicable building codes. Since thecodes of local municipalities might change over time, the structuralembodiment disclosed herein is geared toward the code requirements ascurrently set forth in the 2009 Edition of the ICC InternationalBuilding Code® (ISBN: 1580017258), including those other codesreferenced therein.

TRV Design

Facility 10 has been designed using a number of prefabricated modules soas to speed the process of assembling and disassembling the structure,and may be referred to as a Temporary Radiotherapy Vault (TRV). As shownin FIG. 1, the ground floor is composed of four different modules, eachof which has a generally rectangular footprint. Modules 101, 102 and 103are equal in length and are placed along side each other and module 104is placed across the ends of modules 101, 102, and 103 (right side ofFIG. 1). Alternative configurations or embodiments could incorporatemore than four different modules.

In this illustrated configuration, the treatment room is entirelycontained within module 102. Modules 101, 102 and 103 are designed suchthat, when assembled, they define a number of void spaces 50, 52, 54,56, 58, and 60 around the treatment room 20. These void spaces (i.e.,the vessel) are designed to be filled with a radiation shieldingmaterial M, such as a flowable granular fill having a density range of80-125 lb/ft³. Aligned void spaces (e.g. 50 and 54, 54 and 52, 52 and58) are in fluid communication such that, once filled with the shieldingmaterial, a substantially continuous barrier of the radiation shieldingmaterial is created around the treatment room 20. By remaining in aperpetually flowable state, the granular fill (i.e., the shieldingmaterial M), cannot crack due to settling or seismic events.

Roof modules 105 and 106 are designed so as to be placed above modules101, 102 and 103 and to have their trusses 84 and 82 spanning from theshear wall 64 in module 101 to the shear wall 62 in module 103. Asupporting panel 80 is then mounted between the trusses 84 and 82, andtogether with panels 81, 83 integrated into the roof modules 106, 105supports the shielding material M over the treatment room 20 whilemaintaining a gap 110 between the underside of the panels 80, 81, 83 andthe uppermost portion of the treatment room 20. Alternativeconfigurations and embodiments could incorporate additional roof modulesin lieu of supporting panels. As a result, the load of the shieldingmaterial directly above the treatment room 20 can be distributed throughthe trusses to the shear walls 62, 64 rather than bearing on thetreatment room itself. This gap isolates the treatment room and protectsit from the effects of any foundation shifting or sinking that may occurdue to the excessive weight of the shielding material above it. As shownin FIGS. 2 and 3, the upper level shielding areas 70, 72 and 74 that arenot directly above the treatment room 20 are open to the lower levelvoid spaces 50, 52, 54, 58. Connecting rods 88 span between the upperportions of the trusses 84, 82 and help give shape and support to fabricor membrane roof 92 which is installed once all the shielding materialhas been delivered.

While some of the floor space for control station 22 is provided bymodule 104, it is preferable to have the relevant computer equipmenthardwired to the radiotherapy device 25 in module 102. In this case, thecomputer equipment is provided on a wheeled cart so that it can moveinto the position shown in FIG. 1 from a storage position in module 102.

Radiation Shielding

The precise quantity and desired distribution of radiation shieldingmaterial is dependent on the characteristics of the radiation emittedfrom device 25. As illustrated, the facility 10 is configured to employan isocentrically arranged high energy linear accelerator, whichtypically operates in the range of 4-25 MV. An example would be VarianMedical Systems Trilogy, Palo Alto, Calif. In order to provide theappropriate level of shielding, the total weight of the shieldingmaterial may be 1,000,000 lbs or 2,000,000 lbs or more. To the extentthe linear accelerator is operated at high MV energies (i.e. above 10MV), neutron shielding is provided by lining the treatment room withwood panels and borated polyethylene sheets.

The facility 10 could also be used to perform other types ofradiotherapy, such as gamma knife or high dose rate brachytherapy (HDR),which typically operate in the range of 1-3 MV. The facility 10 may alsobe adapted for use with cyclotrons operating in the range of 10-15 MV orproton accelerators operating in the range of 40-250 MV.

Foundation

Existing Rad Pro Foundations

Existing modular vaults corresponding to U.S. Pat. No. 6,973,758 (i.e.the Rad Pro System) have been constructed on a reinforced concrete slabfoundation in a number of permanent installations. The base of the ProSystem pods was typically elevated several inches above the slab by aseries of stub columns 150 as shown in FIG. 8. These stub columns 150were fabricated from high strength steel and included a hollow verticalsupporting column 153 with horizontal plates 151, 152 at each end. Thevertical column 153 was in the shape of a rectangular solid with asquare horizontal cross section. Shear lugs 154 were welded to theunderside of the bottom plate in the form of a pair of verticalextension plates intersecting at right angles so as to generally form a“+”. In use, a square cross section recess 155 was first provided in theconcrete slab 156. The recess 155 was then filled with grout (not shown)and the shear lugs 154 were set into the grout filled recesses.

New Foundation for TRV

With reference to FIGS. 4-7, the foundation 200 for the TRV (facility10) comprises a pattern (FIG. 4) of elongated beams of reinforcedconcrete. Individual beams of reinforced concrete are conventionallyreferred to as grade beams, since they are typically constructed at orabove grade level. The grade beams for the TRV foundation are recessedseveral inches below-grade (e.g. 3-6 inches). The use of below-grade,grade beams makes it easier to return the site to its original conditiononce the TRV has been removed, since one could simply backfill over thebelow-grade, grade beams.

The pattern includes a number of parallel and orthogonal beams and beamsegments. These beams underlie various portions of the TRV structure andthe layout of FIG. 4 corresponds to the floor plan of FIG. 1. Of note,parallel beams 210 and 212 underlie the elongated sides of module 102and short transverse beams 214, 215 and 216 span between beams 210 and212 at multiple locations along the lengths of beams 210 and 212. Theseshort transverse beams 214, 215, 216 serve to provide a degree ofintegration or coupling between beams 210 and 212, and they also serveto underlie and provide support for the base frame 26 in module 102 towhich the radiotherapy device 25 is mounted. On the other hand, beams214, 215, 216 do not intersect with the outside beams 220 or 230, andthus these outside beams are relatively decoupled from their respectiveinner beam 212, 210. In other words, the presence of beams 214, 215, 216assures that beam 210 is more coupled to beam 212 than it is to beam230.

This is significant because beams 220 and 230 are designed to underlieand provide support to the shear walls 62 and 64 in modules 103 and 101respectively. As explained previously, because of the relationshipbetween platforms 80, 81, 83 and trusses 82, 84, these shear walls 62,64 bear the load of all the suspended shielding material that ispositioned over the treatment room 20. Because this is a large mass ofmaterial, it provides significant inertial resistance to any lateralmovement that would develop during a seismic event (i.e. earthquake). Asa result, in order to satisfy various building codes, it is generallynecessary to have a lateral coupling between the foundation and theshear wall that can withstand the significant lateral stresses. The deadload of the suspended shielding material is also positioned far enoughaway from the therapy room 20, to avoid any impairment to the supportingbeams 214, 215, 216 which may impact the rooms geometry and level.

Keyways

With reference to FIGS. 6 and 7, coupling between the TRV modules andthe foundation grade beams is provided by one of two types of supports.Supports 160 are generally in the form of an I beam and have a planarbase 164 and top plate 162 coupled by a vertical section 166. Support160 is designed to be mounted in an elongated horizontal slot 168 suchas the one formed in grade beam 240. Grade beams 240 and 250 areillustrated in FIG. 4. By virtue of the planar base 164 of support 160being recessed into slot 168, the sidewalls of slot 168 provide lateralcoupling through contact with the sides of base 164 and vertical span166. If the slot 168 is initially too long to provide adequate lateralcoupling contact, such contact can be facilitated by providing groutinto the ends of slot 168.

While illustrated as having only a single vertical span 166, support 160may be reconfigured so as to include additional or different verticalspans between top plate 162 and base 168. For example, vertical platesmay be added to the ends of the support 160 so as to provide additionalcoupling between the top plate 162 and the base 168. These end plateswould be orthogonal to the vertical span 166 and would increase theoverall rigidity of the supports 160.

Supports 260 are similar to supports 160 in that they also have a planarmounting plate 262 and a planar base 264 and the planar base 264 isreceived in slot 222 of a grade beam 221. However, the slot 222 includesa pair of intersecting slots such that slot 222 is considered to beelongated in two orthogonal directions. The base 264 of support 260 isalso of a “+” or intersecting configuration, and in use the base ofsupport 260 is received in slot 222 and engages therewith so as toprovide lateral contact coupling in multiple directions.

Supports 260 may also be supplemented with additional vertical plates.In particular, it is contemplated that four vertical end plates would beattached to the four ends of support 260. Two opposing plates would beattached orthogonal to vertical support 266 and two would be orthogonalto vertical support 268.

Door Cassette

FIGS. 9 and 10 illustrate the door cassette 300 installed in module 101.Door cassette 300 includes a shielding door 40, its surrounding frameparts 320, 330, 324, and a radiation shielding transom area 310 directlyabove the door 40. The entire cassette 300 is configured to be liftedout of module 101 as a whole. When inserted into position, the lowerportion of frame 324 (i.e. the threshold) is recessed into acorresponding opening in the floor of module 101 (not shown). The hingeside of frame 330 abuts against channel steel in the module 101 and isbolted in place via clamps 336. The opposing door side of frame 320 hasa clearance that is filled with shim plate 338 and then the door side offrame 320 is bolted to module 101 via clamps 337. With reference to FIG.1, additional shielding plates 66 are provided in module 101 to provideshielding otherwise lost due to corridor 37, which cannot being filledwith granular fill shielding material M.

Methods of Use

One contemplated method according to the present invention involves theidentification of a radiotherapy facility having an existingradiotherapy device needing to be taken out of service. Typically, afacility would self identify its needs.

Next, a site for a temporary radiotherapy facility is identified. Thesite should be suitably close to the existing facility so as to minimizedisruption, and may be an empty field or parking lot. A foundation forthe temporary device is created at the identified site. The foundationcan be a simple concrete slab, but preferably it is a pattern ofrecessed grade beams as described previously.

Next, a temporary radiotherapy facility is assembled on the foundation.The temporary radiotherapy facility typically includes a radiotherapydevice within a radiation shielding vault, and it may correspond to theTRV previously described. The vault may include at least about 1,000,000lbs of radiation shielding material, such as the granular fill or someother type, as previously described, including water.

When the need for the radiotherapy facility ceases to exist, for examplebecause the renovation has been completed, the facility is removed. Fora typical replacement, this would be less than 12 months. Removal of thetemporary facility may include removal of some or all of the componentsof the TRV and some or all of the radiation shielding material includedin the void spaces.

In one refinement, the TRV is equipped with radiotherapy equipmentsubstantially similar to the equipment to be installed at the existingfacility. In this way, the personnel can receive training on the newequipment while operating in the TRV.

Another inventive method contemplated herein involves maintainingtreatment continuity to a patient population during the renovation orconstruction of a radiotherapy facility. This may be accomplished inconnection with an existing (first) radiotherapy facility having a firstradiotherapy device, wherein services are provided at the existingfacility to a patient population by support staff, the support staffincluding at least one treatment individual. The treatment individualmay be, for example, a doctor, a nurse, a therapist, a dosimetrist, or aphysicist.

A second radiotherapy facility is constructed to treat the patientpopulation on a temporary basis, the second facility having a secondradiotherapy device within a radiation shielding vault, such as the TRVdescribed previously. Upon completion of the temporary facility, thetreatment individual is transitioned to the second facility, and he/sheprovides services at the second facility to the patient populationduring the renovation and/or upgrade of the first radiotherapy facility.Then, upon completion of the renovation and/or upgrade of the firstradiotherapy facility, the treatment individual is transitioned back tothe first facility (or to a newly-constructed third facility) wherehe/she can continue to serve the same patient population. The period oftransition may be occasioned by an equipment modernization and/or theconstruction of a wholly-new facility.

Maintaining Isocenter for Radiotherapy Equipment

In order to be effectively used, radiotherapy equipment must becarefully calibrated. One of the alignment and/or calibrationcharacteristics is referred to as “isocenter” which is a point inthree-dimensional space around which all movable axes of the treatmentmachine revolve. As would be understood, a stable isocenter is critical.In certain applications, isocenter is defined and specified as a spherehaving a radius of no more than 0.5 mm in diameter. The targetedtreatment area, usually a tumor, is placed at isocenter duringtreatment. As various components of the treatment machine (gantry,collimator, and couch) are moved to different angles during thetreatment delivery, it is essential that no part of the machine flex ormove in any manner that would cause the target, at isocenter, to bemissed.

All structures can sink, shift, or even move. They are engineered to dothis without any overall impairment to the structure. A shift in a wall,floor or ceiling in a therapy room, however, has consequences notnormally part of the engineer's design challenge. With a slabfoundation, soil settlement is controlled since the slab can bridge oversettlement areas, just like a sheet of plywood would bridge your shoedepressions in the mud. If there is any settlement, it will be mitigatedby the slab, or at least slowed down so as to happen over a longerperiod of time, typically years.

Rapid settlement in localized areas can have an effect on grade beams,since they do not have the benefit of the monolithic slab. The disclosedapproach, as set forth herein, is to build in tolerance by making thetherapy room an independent structural sanctuary that is not impacted byany settlement caused by the huge shielding mass, especially the massdirectly above the treatment room. This is achieved by creating a sixinch gap between the therapy room structure and the supported shieldingmass above. Further contributing to this achievement is allowing thegrade beams to move independently and further, separating the shieldingmass load from the therapy room load by a suitable distance onindependent grade beams.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character. Only certain embodimentshave been shown and described, and all changes, equivalents, andmodifications that come within the spirit of the invention describedherein are desired to be protected. Thus, the specifics of thisdescription and the attached drawings should not be interpreted to limitthe scope of this invention to the specifics thereof. Rather, the scopeof this invention should be evaluated with reference to the claimsappended hereto.

In reading the claims it is intended that when words such as “a”, “an”,“at least one”, and “at least a portion” are used there is no intentionto limit the claims to only one item unless specifically stated to thecontrary in the claims. Further, when the language “at least a portion”and/or “a portion” is used, the claims may include a portion and/or theentire items unless specifically stated to the contrary. Likewise, wherethe term “input” is used in connection with a device or systemcomponent, such as a fluid processing unit or electrical device, itshould be understood to comprehend singular or plural and one or moresignal channels or fluid lines as appropriate in the context. Finally,all publications, patents, and patent applications cited in thisspecification are herein incorporated by reference to the extent notinconsistent with the present disclosure as if each were specificallyand individually indicated to be incorporated by reference and set forthin its entirety herein.

What is claimed is:
 1. A method for providing radiotherapy while anexisting radiotherapy device is taken out of service, the methodcomprising: providing a radiotherapy facility having an existingradiotherapy device needing to be taken out of service; providing a sitefor a temporary radiotherapy facility to be used while the existingradiotherapy device is taken out of service; providing a foundation forthe temporary radiotherapy facility at the site; constructing atemporary radiotherapy facility on the foundation, the temporaryradiotherapy facility including a radiotherapy device within a radiationshielding vault, the radiation shielding vault including at least about1,000,000 lbs of radiation shielding material; and removing thetemporary radiotherapy facility from the site less than 12 months fromthe time the existing equipment is taken out of service, whereinremoving the temporary radiotherapy facility includes removing theradiotherapy device and the radiation shielding vault from the site. 2.The method of claim 1 wherein the radiotherapy device within thetemporary facility comprises a high energy radiotherapy device.
 3. Themethod of claim 1 wherein removing the facility includes removing atleast about 1,000,000 lbs of radiation shielding material.
 4. The methodof claim 1 wherein the site comprises land which is owned or leased bythe operator of the radiotherapy facility.
 5. The method of claim 1wherein the temporary facility is used while the existing facility isupgraded and/or remodeled.
 6. The method of claim 5 wherein the existingfacility is upgraded to a radiotherapy device substantially similar tothe radiotherapy device in the temporary facility such that use of theradiotherapy device in the temporary facility can serve as training forthe use of the upgraded device.
 7. The method of claim 1 wherein thefoundation comprises a pattern of reinforced concrete beams recessedbelow grade.
 8. The method of claim 1 wherein the temporary facility isconstructed on a plurality of supports extending from the foundation andterminating in an above ground mounting plate.
 9. The method of claim 1wherein the vault includes a treatment room having side walls andwherein the weight of radiation shielding material above the treatmentroom is born by shear walls that are outside the treatment room andspaced from the side walls.
 10. The method of claim 9 wherein each shearwall is positioned over a reinforced concrete grade beam.
 11. A methodfor providing radiotherapy while an existing radiotherapy device istaken out of service, the method comprising: providing a radiotherapyfacility having an existing radiotherapy device needing to be taken outof service; providing a site for a temporary radiotherapy facility to beused while the existing radiotherapy device is taken out of service;providing a foundation for the temporary radiotherapy facility at thesite; constructing a temporary radiotherapy facility on the foundation,the temporary radiotherapy facility including a radiotherapy devicewithin a radiation shielding vault, the radiation shielding vaultincluding at least about 1,000,000 lbs of radiation shielding material;and removing the temporary radiotherapy facility from the site less than12 months from the time the existing equipment is taken out of service,wherein removing the temporary radiotherapy facility includes removingthe radiotherapy device and the radiation shielding vault from the site;wherein the temporary facility is constructed on a plurality of supportsextending from the foundation and terminating in an above groundmounting plate; wherein the supports have a base plate and the baseplate of the supports is provided in recesses in the foundation.
 12. Themethod of claim 11 wherein the base plate of the supports is provided inelongated slots formed in the foundation.